Nike Football Combine, Pittsburgh, PA - Feb. 2010
Devrin Young: 5-6, 162
Results: 4.63 40, 4.03 shuttle, 34-0 PB, 33.2 VJ, 98.25 SPARQ
Young's rushing stats as a junior at Bearden: 222 carries for 1,455 yards (6.6 YPC) & 19 TDs (1 TD every 12 carries)
Nike SPARQ Combine, Atlanta, GA - Mar. 2014
Nathan Cottrell: 5-10.5, 178
Results: 4.35 40, 4.09 shuttle, 39-0 PB, 40.8 VJ, 132.72 SPARQ
Cottrell's rushing stats as a junior at West: 131 carries for 1,922 yards (14.7 YPC) & 22 TDs (1 TD every 6 carries)
Let's see...Cottrell is a bigger, faster, stronger, and more explosive athlete than Young, and during their junior years his per-carry season average was higher than Young's best single-game average, and he averaged at least 7 YPC in all 15 games while Young averaged under 7 YPC in 8 of his 12 games, and he scored TDs at twice the rate as Young.
But other than those things, I don't see much difference between the two.